Process of making shot



Patented July 5, 1932 UNIED PATENT OFFICE ALFONS G. SGHU'RICHT AND GEORGE r. WRIGHT, on ALTON, ILLINoIs, 'ASSIGNORS To WESTERN CARTRIDGE COMPANY, or EAST ALTON, ILLINoIs, A CORPORATION or DELAWARE PROCESS OF MAKING SHOT No Drawing.

This invention relates to projectiles, and more particularly to shot adapted for use in shot guns.

A shot shell is provided with a propellant charge and a shot charge separated by wadding. l/Vhen such a shell is fired, there is a sudden force applied to the shot charge to project the same from the gun, and in view of the fact that these shot are of asoft metal,

such as lead, these shot will become deformed tice be many feet and to such an extent as to greatly affect the accuracy on hitting a target moving across the line of flight of the shot 0 charge. Moreover, this deformity contributes to cause an unequal distribution of the shot laterally of the line of flight and even cause undue scattering so that the pattern of the charge is disadvantageously affected. Moreover, the shoft shot in passing through the barrel of the shotgun not only causes flquling thereof but also deformity of the s 0t.

Ordinary shot are made from alloy of lead, antimony and arsenic. The function of the arsenic is primarily to alfect the fluidity and surface tension of themolten metal which causes the drops to assume truly spherical shape as they fall in the shot tower; however, the arsenic has a decided hardening effect on the shot itself. The'function of the antimony is to harden the lead, the greater the percentage of the antimony the greater the hardness of the resultant alloy; however, when the antimony is increased above a certain limit the shot becomes two brittle for practical use.

One of the objects of this invention, therefore, is to provide shot which is so formed and treated as to prevent deformity when fired from a shot gun while its brittleness is kept within limits toena-ble its practical employment. 1 I

One of the features of this invention re sides in the fact that the shot is subjected Application filed August 4, 1927. Serial No. 210,717.

to treatment which will hardenit' above the original hardness of thealloy of which the shot is composed. In accordance with a" practical embodiment of, this invention, a lead antimony arsenic alloy shot is subjected to a treatment comprising heatingthe lead alloy shot to a temperature near its eutectic point, quenching the same and permitting the same to age.

While the above heat treatment will pro duce ashot whose hardness isgreater than the original hardness ofthe alloy of which the shot is composed, unless the treatment is carefully performed there is danger of they shot becoming deformed due to the temper-v ature of the treatment being so close to the melting point of the alloy. Since the slightest deflection of the shot will affect the'pattern, the treatment unlesscarried out with care is liable to fail in producing a desired shot. Another feature of this invention, therefore, resides in the fact. that previous to hardening, the lead alloy shot is plated with another metal having a greater. fstae bility and a higher melting point. In accordance with a practical embodiment of thisinvention, the'jlead alloy shot is plated with copper to such a thicknessvasto hold the shot in shape during the subsequent heat treatment and the plated shot is thenheated to a temperature near the eutectic pointofthe alloy, and the same mitted to age.

quenched and then per.-

liurther objects features will appear.

from the detail description in which will be disclosed several. emb-odimentsjo'f, this invention; it will, however, be understood that this invention is susceptiblefto various embodiments. 1

In accordance with this invention the core may be of theusual lead alloy shot'formed in the usual manner. as in a shot tower. Where plating, however, is resorted to the use of graphite is reduced as much as possible. As an example, alead alloy of, the composition: 1

is heated to from five to ten degrees centigrade below the eutectic temperature (247 C.) the shot is then quenched in water and allowed to age for a period of at least two weeks. As a result of such treatment it has been found that a, number 6'shot having the above composition and having-an original hardness of 50.1%, measured by the drop test reduction'method, heatedto 24:3" (3., quenched in water and aged. for two weeks, has its hardness increased to reduction. This hardness is approximately. the same from that obtained from a shot'having the following composition;

Lead 9M5 Antimony 4. 75. Arsenic 0. 80

The brittlenessof the shot Will, however, be considerably less. As another example, a having a composition as No. 7 6 chill shot andhavingan original hardness of 39.2% reduction, when given the treatment as described above, resulting in a shot. having a Q hardness of 25% reduction. It will, therefore, be seen that the hardness of shot gun shot can be considerably increased without increasing the brittlenessofan alloy of a given composition.

stated above, on account be the necessity of: carrying the heattreatment to near 7 the melting point, or deforming point of In. order, -however,-to attain agcohering and dense coating of copper, theplatingprocedure is carried out as described in an application of Alfons G. Schuricht, Serial No; 209,195,

filed of even date herewith. Inaccordancewith that treatment, the shot after being thoroughly cleaned insoda ash solution and rinsedwith water, are plated in an alkaline-electrolyte consisting specificallyof cuprous cyanide and sodium cyanide. In

this Way a cohering and dense platingis secured and if the k plating operation is performed in a tumblingbarrel, the platin itself; will be condensed and 'burnished. scribed-in the application referred: to, the plating may be preliminarily in an alkaine electrolyte so, as to secure a flash or film of copper, and this plating is then builtup in anacid electrolyte such as copper sulphate, which may-be-moreexpeditiouslyandconveniently performed a. f p

The platingiscarriedon-untilanenvelope In accordance with another to about 243 C, quenching in water and then allowing the same to agefor a period of at least two weeks. It is found that the copper plated hardened shot is retained in its true spherical shape while thehardness:

the hardening of is increased, not only by the hardening of the core itself, but also by the entire shot, plating. V deposit a comparatively thin plating on the shot while still retaining the. advantages.

It will, therefore,be seen that the invention accomplishes its objects. A shot iscprovided whichis ofsufiicient stability as to .pre-

vent deformity thereof when .fired from a shot gun; accordingly, not only will string-v ing-ofthe shot be decreased, but the pattern will be improved. Where the shot is plated as well as hardened, not only isits stability high but the-plating being non-fouling, foul;v

ing of the shot gun barrel will be prevented.

jectiles, rifles (.22 calibre) andballs for use in shot shclls- In case of riflebullets, not only will the bullet as a whole behardened, butthe driving-band willbe given increased stability.

This driving band can 1 be rolled or swaged as described in application of S; F. Briggs, SerialN'o. 144,585, filed Oetober28, 1926, in order to not only additionally condense but also size and conform the driving band to the rifle. I It will, furthermore, be understood that certain features, operations and sub-combinations are. of utility andmay be employed without reference to other features, operations and'usub-combinati'ons; that is-"contemplated by and is within'the scope of-the appended claims. It is, furthermore obviousthat various changes maybe made indetails of construction and operation within: the scopeof the appended claims without departing from the spirit-ofthis-invention. It is, therefore, to be understood that this inven: tion is not to belim-ited to the specific details and operation-s described. V Y Havingthus described the invention what isclaimed isr I 1 1 i v r .1. In the art ofmaki'ngshot,theprocess comprising, plating lead alloy shot and hardening the plated shot.

2; the art of making shot, the .process 3' r duetothe application of the. V In this way it is only necessary to.

Vhile the invention is applicabletoshot: v for shot shells it will be understood, that as to some'ofits features the inventionisapplicable to other forms and'types' ofpro such as bullets for small calibre ifs comprising, plating lead alloy shot with a metal having a higher melting point, heating the plated shot to a temperature near the eutectic point of the alloy, quenchingthe same and permitting'the same to age.

3. In the art of making shot, the process comprising, plating lead alloy shot with copper and hardening the plated shot.

4. In the art of making shot, the process comprising, plating lead alloy shot With copper, heating the plated shot to a temperature near the eutectic point of the alloy, quenching the same and permitting the same to age.

5. In the art of making shot, the process comprising, plating lead alloy shot With copper successively in alkaline and acid electrolytes, heating the plated shot to a temperature near the eutectic point of the alloy,

quenching the same and permitting the same to age.

In testimony whereof I hereby affix my signature this 29th day of July, 1927.

ALFONS G. SCHURICHT.

In testimony whereof I hereby aflix my signature this 29th day of July, 1927.

GEORGE T. WRIGHT. 

